Love how seemingly random things line up

So I did the quest Waking Nightmare in Dawnstar, and afterward stopped in the apothecary shop to do business. The nice lady asks me to fetch the Ring of Pure Mixtures for her, and it's a random location.

Where does it send me? Forsaken Cave, home of the White Phial.

So I hop over to Windhelm quick, stop at the apothecary there, and grab the associated quest. Quite fitting that the White Phial and Ring of Pure Mixtures would be found together.